Replace terrarium examples with mapterhorn (#618)

* update examples to maplibre 5.13.0

openlayers/examples/raster.html

@@ -17,8 +17,8 @@
         <script type="text/javascript">
           const rasterLayer = new ol.layer.WebGLTile({
             source: new olpmtiles.PMTilesRasterSource({
-              url:"https://r2-public.protomaps.com/protomaps-sample-datasets/terrarium_z9.pmtiles",
-              attributions:["https://github.com/tilezen/joerd/blob/master/docs/attribution.md"],
+              url:"https://download.mapterhorn.com/planet.pmtiles",
+              attributions:["https://mapterhorn.com/attribution/"],
               tileSize: [512,512]
             })
           });